GLUSCAN Solution for injection Ref.[50604] Active ingredients: Fludeoxyglucose ¹⁸F

Distribution

Fludeoxyglucose (¹⁸F) is a glucose analogue which is accumulated in all cells using glucose as primary energy source. Fludeoxyglucose (¹⁸F) is accumulated in tumours with a high glucose turnover.

Following intravenous injection, the pharmacokinetic profile of fludeoxyglucose (¹⁸F) in the vascular compartment is biexponential. It has a distribution time of 1 minute and an elimination time of approximately 12 minutes.

In healthy subjects, fludeoxyglucose (¹⁸F) is widely distributed throughout the body, particularly in the brain and heart, and to a lesser degree in the lungs and liver.

Organ uptake

The cellular uptake of fludeoxyglucose (¹⁸F) is performed by tissue-specific carrier systems which are partly insulin-dependent and, thus, can be influenced by eating, nutritional condition and the existence of a diabetes mellitus. In patients with a diabetes mellitus a reduced uptake of fludeoxyglucose (¹⁸F) into the cells occurs due to a changed tissue distribution and glucose metabolism.

Fludeoxyglucose (¹⁸F) is transported via the cell membrane in similar fashion to glucose, but only undergoes the first step of glycolysis resulting in formation of fludeoxyglucose (¹⁸F)-6-phosphate which remains trapped within the tumour cells and is not further metabolised. Since the following dephosphorylation by intracellular phosphatases is slow, fludeoxyglucose (¹⁸F)-6-phosphate is retained in the tissue over several hours (trappingmechanism).

Fludeoxyglucose (¹⁸F) passes the blood-brain barrier. Approximately 7% of the injected dose are accumulated in the brain within 80-100 minutes after injection. Epileptogenic foci exhibit a reduced glucose metabolism in the seizure free phases.

Approximately 3% of the injected activity is taken-up by the myocardium within 40 minutes. The distribution of fludeoxyglucose (¹⁸F) in normal heart is mainly homogenous; however, regional differences of up to 15% are described for the interventricular septum. During and after a reversible myocardial ischemia, an increased glucose uptake occurs into the myocardial cell. 0.3% and 0.9-2.4% of the injected activity are accumulated in pancreas and lung.

Fludeoxyglucose (¹⁸F) is also bound to a lesser extent to ocular muscle, pharynx and intestine.

Binding to muscle may be seen following recent exertion and in the event of muscular effort during the examination.

Elimination

Elimination of fludeoxyglucose (¹⁸F) is chiefly renal, with 20% of activity being excreted in urine in the 2 hours following injection. Binding to renal parenchyma is weak, but because of renal elimination of fludeoxyglucose (¹⁸F), the entire urinary system, particularly the bladder, exhibits marked activity.

Toxicological studies with mice and rats have demonstrated that with a single intravenous injection of 0.0002 mg/kg no deaths were observed. Toxicity with repeated administration was not performed because GLUSCAN 500 is administered in a single dose. This medicinal product is not intended for regular or continuous administration.

Mutagenicity studies and long-term carcinogenicity studies have not been carried out.